The El Al plane that had to make an emergency landing at Ben-Gurion Airport on Monday may have suffered from either metal fatigue or a structural flaw in the Boeing jet itself, and not from a maintenance failure, according to an initial investigation into the incident.

The probe has yet to reach any definite conclusions. But if the problem with the plane's undercarriage was indeed structural, then it could potentially affect all Boeing 777s.

As a result, two experts from Boeing arrived in Israel yesterday to participate in the probe, which is being headed by Yitzhak Raz, the Transportation Ministry's chief aviation accidents investigator. The U.S. National Transportation Safety Board is also participating.

So far, however, Boeing has neither grounded its 777 fleet nor issued new maintenance or inspection guidelines.

Haaretz has learned that the faulty section was not part of the original plane, but rather a piece that had been refurbished by an overseas company licensed by Boeing to do the work.

The problem that caused the plane to make an emergency landing was a crack that appeared between the undercarriage and the body of the plane. This could have caused the plane to crash when it tried to land.

The incident occurred on an El Al flight to Newark that took off at 1:34 A.M. Monday morning carrying 259 passengers. Shortly after takeoff, the crew noticed signs of a technical problem with the undercarriage. Captain David Kenet therefore decided to turn around and make an emergency landing at Ben-Gurion, as called for by standard safety regulations.

After first circling around for several hours to dump his fuel, and thus minimize the risk of a fire, Kenet landed the plane safely at 5:50 A.M. The passengers were then transferred to other flights.

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